Power reciprocating saws include jigsaws and other reciprocating saws generally referred to in the trade as “recip” saws. These saws incorporate reciprocating shafts for driving generally linear saw blades along a predetermined path so as to provide one of a rectilinear or orbital cutting action.
In a conventional manner, the saw blades used with such power tools are attached to the reciprocating drive shafts through a blade holder having a slot for receiving the saw blade and a set screw which is received in a hole in the blade. The blade is clamped in place relative to the reciprocating drive shaft through tightening of the set screw. A particularly useful alternative to the set screw includes a clamping lever and a biasing member. The lever cooperates with the biasing member to clamp the blade in place. More particularly, when the lever is placed in its unclamping position it overcomes the biasing member that otherwise maintains the blade against a reciprocating drive shaft.
In addition, reciprocating saws typically include a shoe. The shoe is placed against the workpiece to assist in controlled cutting. The shoe also determines the depth the saw blade will extend through and beyond the work piece. In many known arrangements, the shoe can be adjusted in a direction parallel to the blade. When cutting a piece of plywood the operator may wish to prevent damage to other objects lying below the plywood. Thus, the operator may adjust the shoe to such a position that the blade penetrates and cuts the plywood without damaging the object therebelow.
To be useful an adjustable shoe must be clamped or locked in place. Known adjustment and lock mechanisms sometimes include a post with the following features: a plurality of locking slots; a positioning slot on a face perpendicular to the locking slots; a stop plate; a channel; and a removal slot. An equally complicated plate mechanism cooperates with the post to adjust and lock the shoe in place. Typically the mechanism includes a locking plate, a locking portion, and a positioning portion. A spring biases the lock mechanism in a position wherein the lock mechanism prevents the plate mechanism to lock the shoe in a position selected by the operator. Additionally, a separate mechanism clamps the saw blade in place.
The various slots, plates, channels, and portions each require separate machining, which increases the cost of the tool. Moreover, not only must the operator clamp the blade in place, the operator must also lock the shoe in place, and if removal of the shoe is required the operator must also rotate the post. Accordingly, work with the tool stops while the steps of clamping the blade and locking and removing the shoe take place. Thus, the pace of work slows down thereby imposing further operating costs on the operator. Moreover, as the complexity of the work increases (i.e., the number and frequency of shoe adjustments increases) the greater the work slow down.
Accordingly, a reciprocating saw shoe locking mechanism that is easy and inexpensive to manufacture and convenient to use is desirable.